a. Field of the Invention
The present invention generally pertains to arc welding and more particularly to electrode holders used during arc welding.
b. Description of the Background
Many arc welders use electrode holders to keep an electrode in a fixed position while welding and allow the metal in the electrode to fill the weld. Typical copper electrode holders are “tong-type” that grip an electrode between a pair of openable jaws or “tongs”; in some cases, the tightness of the tongs may be adjustable by a screw or spring. Other electrode holders may use a “pistol grip” that securely grips an electrode but requires two hands to remove a used electrode and insert a new one, thus reducing efficiency.
During a welding project, an electrode may be bent at various angles to allow welding in unusual positions. A welder typically bends an electrode by hand while the electrode is gripped by the tongs of the electrode holder. The stiffness of the electrode and the brute strength needed to make it bend often cause either the electrode to pop out of the tongs or the tongs to be pried open and thus lose their grip on the electrode. To succeed in bending an electrode, a welder may permanently bend the tongs of his electrode holder until the tongs have a permanently looser grip on succeeding electrodes, especially if succeeding electrodes have a smaller diameter.
Once tongs have been bent, a welder must exercise constant care to ensure that an electrode remains tightly gripped, as even slight movement of an electrode within the tongs may severely damage a welding project. During welding projects where a welder uses hundreds of electrodes (and bends many of them by hand) per day, a copper tong-type electrode holder may require replacement every 2-4 weeks because it can no longer grip an electrode tightly enough to allow efficient and accurate welding. The bending process may also injure or cause permanent damage to the wrists of a welder because of the brute strength needed for bending. U.S. Pat. No. 2,806,126 (Gladen) adds grooves to tongs to help them grip an electrode more tightly, but even grooves cannot give an open-jawed electrode holder sufficient gripping strength to withstand constant electrode bending.
Another problem with many tong-type holders is that over time, their metal content may make them too hot to hold properly because of the extreme temperatures generated during welding. U.S. Pat. No. 6,184,492 (Busopulos) uses a handle that keeps an electrode holder cool and even allows a welding lead to be fed through the handle and conveniently connected to the electrode holder—but the handle must be removed from the electrode holder to accomplish this.
It would thus be advantageous for an electrode holder to have a closed-end structure that prevents long-term gripping problems and eliminates the need for the constant checking of electrode position within an electrode holder that is common with open-jawed electrode holders. It would also be advantageous if the electrode holder were made of a stronger metal than copper and contained a deeply-grooved hole that allows tighter clamping onto an electrode and makes bending an electrode by hand easier. It would be further advantageous if the electrode holder had a comfortable handle that could keep the electrode holder cool to the touch and allowed a welding lead to be fed through the handle and conveniently connected to the electrode holder without removing the handle of the electrode holder.